Chromatography Forum

Hello people-

I'm trying to run an HP 5890 and for some reason my pressure isn't holding on the front injector.

I've done (and redone) all maintenance to make sure that everything was screwed in and seated correctly. Checked for leaks using a leak detector and found nothing.

Checked and double checked: septum/o-ring/injector nut/ferrule/Presstight connector

Any suggestions? I'm trying to think of whether or not I've overlooked something, but it seems like I've tried everything.

I assume you are using a capillary column.

Have you looked for a leak in the column itself?

A cracked column can lose a lot of pressure.

best wishes,

Rod

I assume you are using a capillary column.

Have you looked for a leak in the column itself?

Yes, I am and yes I did check the column. Still not sure what's going on.

Does this 5890 have EPC or manual pneumatics control.

Has the leak testing only been confined to the injection port area itself, or have you also tried leak checking the pneumatics.

What column are you using and what conditions are you trying to achieve regarding flow and split ratio.

Gasman

check the splitter vent flow rate and the septum purge vent flow rate

tell us the details of the pressure and the split ratio and column flow rate

don't be bashful.

best wishes,

Rod

This 5890 has an EPC.

Not being bashful, but I reset the GC (was getting a Power/Cable Switch error in addition to not holding pressure), restarted the software, and it was good to go.

For the record, I'm using an RTX-CLPest column.

Have you check your split trap?
Have you check instrument configuration about gas type, column lenght?